Improvement in low-water alarms for boilers



F. s. DAVENPORT, OF JE RSEYVILLE, ILLINOIS. Letters .Patentll/o. 73,168, dated January 7, 1868.

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TO ALL WHOM IT MAY CONCERN:

Be-it known that I, F. S. DAVENPORT, of Jerseyville, in the county of Jersey, and State of Illinois, have invented a. newand improved Low-Water Alarm; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference being .had to the accompanying drawings,.forming part of this specification.

-This invention relates to a new and improved device for ascertaining the height of water in a steam-boiler; and it consists in operating a valve by a float, whereby an alarm is given when the water in the boiler falls below the required line, as will be hereinafter described. L i

The drawing represents a vertical central section of the instrument, showing the manner of its arrangement.

A represents the shell of the boiler. B is the water-line. G is a tube, whichis screwed into the shell of the boiler, on the top end of which there is a tubular cup, D, attached by a screw-thread, as seen in the drawing. The lower end of this cup is counte rsunk. .and forms a seat, 9, for a conical valve. E is an interior tube, which passes down into the boiler, where it is attached to a float, F, whi'ch'rests upon the surface of the water, as seen. The tube E is smaller indiameter than the bore of the tubeC, so that the steam may escape up through the annular space between the two. The interior of the tube E is in communication with the interior of the -float F through the orifice j, for the purpose of producing an equilibrium of pressureon the float to prevent its collapsing. The top of the tube E is closed and forms a conical valve, It, which fits the seat in the cap D., When the water in the boiler is at the proper height, the valve-h will be lifted by the float to its seat, and close the aperture through the cap, and prevent the escape of steam, but if the water falls too low, or below the desired point, the valve will bewithdrawn, and steam from the boiler will pass up around the tube E and escape from the cup, and thereby give the alarm. A steam-whistle may be placed on the tube 0 instead of the cup D, if desired. It will be seen that in this instrument there are nojoints to leak or get out of order, and that, the working parts, being above the water-lev'eL-all} obstruction on account of the accumulation of dirt or sediment is avoided, and that perfect reliability of action is insured.

Having thus described my invention, I claim a' s new, and desire to secure by Letters Patent- 1. The construction and arrangement of'the hollow tube 0, provided at its upper end with the screw-plug D, having valveseat, g, the hollow tube E fitting in tube 0, and having the opening j communicating with the interior of the float, and provided at its upper end with the pointed valve It, all operating asdescribed for the .purp ose specified. 4 p v v 2. In combination with the outer and inner tubes C and E, when arranged as described, the valve-scat g, the valve 72, and the orifice j, substantially as and for the purposes set forth.

F. S. DAVENPORT.

Witnesses:

DAVID E. Ross,

R. Q. Monnnous. 

